<!DOCTYPE html>
<html lang="zh-CN">
  <head>
    <meta charset="utf-8" />
    <meta http-equiv="X-UA-Compatible" content="IE=edge" />
    <meta name="viewport" content="width=device-width, initial-scale=1" />
    <title>bootstrap 初体验</title>
    <link
      href="https://cdn.jsdelivr.net/npm/bootstrap@3.3.7/dist/css/bootstrap.min.css"
      rel="stylesheet"
    />

    <style>
      .ad{
        width: 200px;
        height: 200px;
        background: linear-gradient(to right bottom, #aef, #458);
        position: absolute;
        right: 0;
        bottom: 0;
      }
    </style>

  </head>
  <body>
    <!-- <div class="ad visible-lg"></div> -->
    <!-- <div class="ad hidden-xs"></div> -->
    <div class="ad hidden-xs hidden-sm"></div>
    <script src="https://cdn.jsdelivr.net/npm/jquery@1.12.4/dist/jquery.min.js"></script>
    <script src="https://cdn.jsdelivr.net/npm/bootstrap@3.3.7/dist/js/bootstrap.min.js"></script>
    <script src="https://cdn.bootcdn.net/ajax/libs/holder/2.9.8/holder.min.js"></script>
  </body>
</html>
